I have an 05 LLY and am loving this truck! Last week I installed the Diablo Sport Predator, and I have a question for other members running this tuner. I am currently running the tuner on the 40HP setting, and I notice when I get on the go pedal the temps rise to 210 VERY rapidly. If I back off the go pedal the temps very rapidly drop back to normal winter temps 180-190(ish). Now when I say I get on the go pedal I don't mean mash it to the floor I just mean enough to get on the freeway, pass, burn a ricer :D etc. I'm just wondering if this temperature variation is normal for the predator as stock my temperature hits 180 and doesn’t budge. If I decide to bump up to the 65HP setting (waiting on my pyrometer, come on Santa) will I see similar fluctuations? Just curious as to how other vehicles are behaving, thanks for the replies.<O:p</O:p

EGT's and water temp are unrelated.

You can melt a piston with a cold engine, or blow a head gasket while cruising.

Your truck will spend most it's life at 210 except in the winter. It's the normal full operating temp, and it runs best there. In the winter, you won't reach full temp unless towing or otherwise giving the engine some load.

Gauges are a good idea, but on a 40HP tune and no towing? Not necessary.

Thanks for the reply McRat, actually I’m currently playing with the 40HP “tow” tune as I have a trip to make to Oregon with approx 6k on the trailer, just letting the Alli learn this HP level before I make the trip. Diablo Sport advertises that the 40HP tune can be used to pull up to the listed max for the vehicle (which I won’t ever hit), I’m sure like most folks I’ll use my truck to pull a load several times a month vs. the hardcore users who pull heavy loads several times per week. My max load will probably be around 11-12k with tractor and generator, which will be from Reno to Vegas and back during the heat of the Summer.
While I’m running empty right now (again letting the Alli learn before I tow) I was surprised to see my engine temps fluctuate so rapidly and so much. With the stock tune I can bury the throttle and maybe see the temp twitch I’d estimate maybe 10 degree variation, but with the 40HP Predator tune loaded my gauge will jump to 210 with just a bump of the throttle. Let off the throttle and the temps move back to the 180 range almost as rapidly, that’s a 30 degree swing from 180 to 210 back to 180 in maybe a minute. I’m just wondering if this is normal. Seems to me like these wild fluctuations would be detrimental to the health of my Diesel.
Does anyone else running the Predator (any tune) notice that their temperature gauge actually works vs. hitting normal operating temps and sitting there like a stone?

I've towed up I-5 in cool weather both towing a small load and empty. The truck runs around 180, or mabye a bit cooler, on level ground. But soon as I hit a grade the temps immediately go to 210. Get to the top of the grade and they immediately drop. No tunes, no box, just stock. So yes,
it sounds normal.

Jim

Thanks for that info jholly, I guess I’m just a bit paranoid as the Predator is still fairly new to the LLY and to my new 40k baby. I just wanted to compare my experience with that of others with the Predator to see if this is normal behavior, which it sounds like it just might be.

As a side note it sure is fun to watch the fuel gauge go down while the temp gauge goes up when you’re putting the Hammer Down on a ricer with a fart can. ):h